World champion Ronnie O'Sullivan has called a time-out on his snooker career in a dramatic move that casts doubt on whether he will ever play again.

The 36-year-old wrote to World Snooker chairman Barry Hearn to confirm what he told the veteran sports promoter last week: that his season is over before it has properly begun. The precise reasons were not disclosed, although it is known O'Sullivan has battled depression and recently suffered badly with glandular fever.

GOLF: Ernie Els had his name removed from the European Tour money list, and The Open champion is no longer eligible for the £5million DP World Tour Championship in Dubai in two weeks or a share of the £2.4m end-of-season bonus pool.

Tour members need to play 13 counting events in a year and the South African's joint runner-up finish at the WGC-HSBC Champions in China this weekend was his 10th on the circuit.

To stay on the Order of Merit and play in Dubai, Els would have had to compete in this week's Singapore Open and then either the South African Open or Hong Kong Open next week, but his next scheduled tournament is the Asian Tour's Iskandar Johor Open in Malaysia on December 13-16.

FORMULA ONE: Paul di Resta is relishing the prospect of becoming an unofficial 'team leader' for Force India next season. With Nico Hulkenberg off to Sauber, question marks remain as to who will be the Scots' team-mate.

Di Resta said: "I feel I've enough experience having been a part of this team long enough. It's hard work, but I've learned a lot over the years."